Containers for the long-term storage of radioactive materials must be mechanically stable, corrosion-resistant and sealed. The vessel of the container is therefore made from a material selected from the group including cast steel or cast iron to ensure that the container has the required mechanical stability.
The resistance of cast steel or cast iron to corrosion is unsatisfactory for the purposes of long-term storage. It has therefore already been proposed that a corrosion-resistant protective layer be applied to the exterior of the cast steel or cast iron vessel of the container. Ceramic, graphite or enamel are suitable for forming the protective layer because of their good resistance to corrosion. It is also possible to use metallic corrosion-resistant layers which are applied galvanically or by thermal spraying. The operation of coating the large surface area of the vessel of the container is a technically expensive one. Due to the different properties of the material of the protective layer and the metal base body of the vessel of the container, there are differences in expansion, which result in stresses between the two contiguous surfaces. There is thus the danger of stress cracks being formed and the protective layer becoming detached.